If you have the capability to test IPS daughter cards all by themselves, not installed inside an M2x amplifier, and if you have an oscilloscope with at least 75 MHz bandwidth, then by all means, try all opamp types in all boards and have a lot of fun! The combinations which do oscillate will be identified and discarded, before they can be installed inside the M2x chassis and before they can destroy your loudspeakers. Test using a 10 kHz, 1V PP square wave input.
If you can't test IPS daughter cards in vitro, I recommend being extremely cautious. At the very least, disconnect your speakers and move them to another room, then connect 8 ohm 100 watt dummy load resistors to the M2x before testing. Use the 75+ MHz scope to sniff for oscillations right at the IPS daughter card connection bolts, and also at the speaker terminals. If you detect oscillation, cut the power right away, you don't want to subject your Edcor transformers to that junk for very long.
I, personally, am not going to install any opamp type other than AD797, in my Cedarburg cards. To me, Cedarburg is a support vehicle for AD797 and nothing else. You of course are free to do as you please, with my blessings and good wishes of course. Cedarburg will undoubtedly operate correctly and play music, with a Fairchild uA741 opamp installed, for example. But I don't plan to audition that combination, myself. Nor do I plan to ever install an AD797 in any other board except Cedarburg.
Everyone would agree that the IPS7 card is unquestionably more flexible than either Tucson or Cedarburg, since IPS7 can accept either single or dual opamp chips. And, thanks to low cost adapter cards like these, you can experiment with opamps that are only sold in surface mount packages. {try the OPA209, very few people have.} On the other hand, the PCBs for Tucson are "free", you get them as part of the M2x board set sold in the Store, without the oogah-boogah scary process of ordering boards from an overseas Fab, or seeking out a generous soul who will sell you a couple of their excess boards. Also, Tucson has far fewer components on the board, offering fewer opportunities to make a mistake (either in building or in parts-ordering), so Tucson is more likely to work perfectly on the first try.
Finally, keep in mind: it's your hobby to pursue in whatever way you like. Do as you please and enjoy the experience. It's entertainment.
_
If you can't test IPS daughter cards in vitro, I recommend being extremely cautious. At the very least, disconnect your speakers and move them to another room, then connect 8 ohm 100 watt dummy load resistors to the M2x before testing. Use the 75+ MHz scope to sniff for oscillations right at the IPS daughter card connection bolts, and also at the speaker terminals. If you detect oscillation, cut the power right away, you don't want to subject your Edcor transformers to that junk for very long.
I, personally, am not going to install any opamp type other than AD797, in my Cedarburg cards. To me, Cedarburg is a support vehicle for AD797 and nothing else. You of course are free to do as you please, with my blessings and good wishes of course. Cedarburg will undoubtedly operate correctly and play music, with a Fairchild uA741 opamp installed, for example. But I don't plan to audition that combination, myself. Nor do I plan to ever install an AD797 in any other board except Cedarburg.
Everyone would agree that the IPS7 card is unquestionably more flexible than either Tucson or Cedarburg, since IPS7 can accept either single or dual opamp chips. And, thanks to low cost adapter cards like these, you can experiment with opamps that are only sold in surface mount packages. {try the OPA209, very few people have.} On the other hand, the PCBs for Tucson are "free", you get them as part of the M2x board set sold in the Store, without the oogah-boogah scary process of ordering boards from an overseas Fab, or seeking out a generous soul who will sell you a couple of their excess boards. Also, Tucson has far fewer components on the board, offering fewer opportunities to make a mistake (either in building or in parts-ordering), so Tucson is more likely to work perfectly on the first try.
Finally, keep in mind: it's your hobby to pursue in whatever way you like. Do as you please and enjoy the experience. It's entertainment.
_
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Usually there are some strange "overlay" on the test sine signal. Then if the timebase is turned all the way out to max. sweep velocity the details of the additional frequency content can be viewed. My old Tek 2225 is rated 50Mhz but they usually go a bit higher so I guess I could see something at 50 - 100 MHz. I think an analog scope is an advantage here.
You really can’t go wrong. When someone like Mark so generously provides a new design the PCBs are only a few dollars.
Regards,
Dan
Spare Cards
You got it! I only need 4. You have 2. The first two DIYers who ask for a pair get them.
Just pay the postage from 83856 USA and they are yours. Speak up now.
Grataku, send me a PM with your address and we can figure out the postage.
You got it! I only need 4. You have 2. The first two DIYers who ask for a pair get them.
Just pay the postage from 83856 USA and they are yours. Speak up now.
Grataku, send me a PM with your address and we can figure out the postage.
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I should look at that for same reasons. I've been using DHL and the freight is more than you paid total. Service is good though.
Don
Very funny. I admit I was tempted to order more but I am not in a good position at the moment to be mailing out dozens of boards like you are so willing to do. In the future I'll take you up on the suggestion.
I think they have a sale going on boards. They cost less than a stamp. Amazing.
I think they have a sale going on boards. They cost less than a stamp. Amazing.